6-fluoro-17 alpha, 21-epoxy-1,4-pregnadienes



6-FLUOR0-17u,21-EPOXY-1,4-PREGNAD1ENES George B. Spero, Barney J.Magerlein, William P.

Schneider, and John A. Hogg, Kalamazoo, Mich., assignors to The UpjohnCompany, Kalamazoo, Mich., a corporation of Michigan No Drawing.Application June 9, 1958 Serial No. 740,592

2 Claims. (Cl. 260-43955) This invention relates to novel steroids,6,21-difluoro- 1113,17 dihydroxy 1,4 pregnadiene 3,20 diones and 6,21difluoro 17a hydroxy 1,4 pregnadiene 3,11,20-triones, and tointermediates and processes for making the same. It relates particularlyto 6m,21-difil101'0- 11,13,170: dihydroxy 1,4 pregnadiene 3,20 dione (1dehydro 60:,21 difluoro 21 desoxyhydrocortisone) and 6u,2l difluoro 17o:hydroxy 1,4 pregnadiene 3,11,20 trione (1 dehydro 6a,21 difluoro21-desoxycortisone) intermediates in the production thereof, andprocesses for their production.

The novel 1 dehydro 6,21 difluoro 21 desoxy hydrocortisones and 1dehydro 6,21 difluoro 21 desoxycortisones of the present inventionpossess a high order of glucocorticoid and anti-inflammatory activity.They are useful in the treatment of various arthritic conditions and inthe control of inflammatory conditions due to bacterial infections orallergic reactions of skin or mucous membranes. The compounds possessdiuretic activity in that they cause a loss of salt and water whichmakes them especially valuable in the management of chronic congestiveheart failure and in the treatment of cirrhosis of the liver, thenephrotic syndrome, and the treatment of eclampsia and pre-eclampsia.For example, 1 dehydro 60:,21 difiuorohydrocortisone has glucocorticoidactivity about twelve times that of Kendalls Compound F andanti-inflammatory activity about ten times that of Kendalls Compound F.

The new compounds and the process of the present invention areillustratively represented by the following flow sheet and formulae:

H, CH3

onion (IJHZOSOZR =0 0:0 ----on ---0H United States Patent 0 2,884,420Patented Apr. 28, 1959 wherein R is an organic radical, particularly ahydrocarbon radical containing up to and including ten carbon atoms,such as ethyl, phenyl, tolyl, naphthyl, or the like, with methylpreferred.

The process of the present invention comprises treating 6 fluoro11}3,17u,21 trihydroxy 1,4 pregnadiene 3,20 dione (1 dehydro 6fluorohydrocortisone) (I) with an organic sulfonyl halide to obtain thecorresponding 2l-ester, (II), a 21-alkyl or 21-arylsulfonate of 6 fluoro1l}9,17a,21 trihydroxy 1,4 pregnadiene-3,20-dione. Treating the thusproduced 21- alkyl or arylsulfonate of 6-fluoro-1lfl,17a,2l-trihydroxy-1,4-pregnadiene-3,20-dione (II) with an iodinating agent yields 6 fluoro110,170: dihydroxy 21 iodo 1,4 pregnadiene-3,20-dione (III).Fluorination of 6-fiuoro- 11 8,1704 dihydroxy 21 iodo 1,4 pregnadiene3,20 dione (III) produces 6,21-difluoro-11 8,17a-dihydroxy-1,4-pregnadiene-3,20-dione (IV). Compound (IV) can also be obtained byfiuorinating directly 6-flll0l0-11}3,17a,21- trihydroxy 1,4 pregnadiene3,20 dione 21 meth anesulfonate (II). Oxidation of6,21-diflll0r01l}3,17adihydroxy-1,4-pregnadiene-3,20-dione produces6,21-difluoro a hydroxy 1,4 pregnadiene 3,11,20 trione (V). Similarly,when the ll-keto analogue (l-dehydro-6-fluorocortisone) is utilized asstarting material in the above series of reactions, 6,2l-difluoro-l78-hydroxyl,4-pregnadiene-3,l1,20-trione (V) is produced directly Withoutthe step of oxidation of the llfl-hydroxyl.

Administration of the novel steroids can be in conventional dosageforms, such as pills, tablets, capsules, syrups or elixirs for oral use,or in liquid forms which are adaptable to the natural and syntheticcortical steroid hormones for injectable products. The novel compoundscan also be administered topically in the form of ointments, creams,lotions, and the like, with or without coacting antibiotics, germicidesor other materials forming advantageous combinations therewith.

As will hereinafter be described in greater detail, these compounds areadditionally useful as intermediates in the production ofl-dehydro-6,21-difluoro-9u-halo-21- desoxyhydrocortisone andl-dehydro-6,21difluoro-9ahalo-2l-desoxycortisone. The Qua-113.10derivatives are of particular importance because they possess acombination of high anti-inflammatory and glucocorticoid properties withlow concomitant mineralocorticoid activities.

The starting steroids for the compounds and process of the presentinvention are 1-dehydro-6a-fluorohydrocortisone or1-dehydro-Gfi-fluorohydrocortisone or the corresponding ll-ketocompounds and are prepared in accordance with the procedures ofpreparations 1 through 12 herein.

In carrying out the process of this invention,l-dehydro-6-fluorohydrocortisone or 1-dehydro-6-fluorocortisome istreated with an organic acid sulfonyl halide such as methanesulfonylchloride, toluenesulfonyl, chloride, toluenesulfonyl bromide,benzenesulfonyl chloride, naphthylsulfonyl chloride, or the like; themethanesulfonic acid halides, especially methanesulfonyl chloride, beingpreferred. In the preferred embodiment, the starting steroid is reactedwith the'alkyl or aryl sulfonyl halide in a solvent such as pyridine,benzene, toluene, or the like. Suflicient amine base, e.g., pyridine,should be added to react with any halogen acid formed. The sulfonylhalide reaction is conducted at a temperaturebetween minus ten and plussixty degree Centigrade, providing at the lower temperature the solventhas not solidified. Thus, for pyridine, dioxane, toluene, or the like,temperatures in the range of zero to ten degrees centigrade can be used,while for benzene only temperatures above five degrees centigrade aresuitable because of the relatively high melting point of the lattercompound. The reaction time is usually between about thirty minutes andeight hours, after which the product, 6-fluoro-1113,17a,2l-trihydroxy-1,4-pregnadiene 3,20 dione 21 alkyl or arylsulfonate, is recovered in a conventional manner, such as by evaporatingthe solvent to produce a residue, followed, if desired, by mixing theresidue with water and extracting the purified material therefrom. Forextraction, solvents such as methylene chloride, chloroform, carbontetrachloride, benzene, ether, toluene, or, the like, can be. used.Removal of theextraction solvent bydistillation leaves theZI-alkyl oraryl sulfonate.

The 6 fluorol1/8,17u,2l-trihydroxy-l,4 pregnadiene 3,20-dione 2l-alkylor aryl sulfonate is then reacted with a fluorinating agent such aspotassium fluoride, silver fluoride. or antimony fluoride in an inertsolvent such as dirnethylsulfoXi-de, acetonitrile, dimethylforrnamide orethylene glycol solution, potassium fluoride in dimethylsulfoxidebeingpreferred. The reaction is advantageously conducted under continuousheating, and it proceeds generally for a period of about six to 24hours,'fifteen to twenty hours being usually suflicient. The reactionmixture is then diluted with an organic solvent such asmethylenechloride, chloroform, benzene, and the like, and purified in aconventional manner, as, for example, by chromatography or solventextraction.

An advantage of this fluorinating method is that it is productive ofminor amounts of 6-fluoro-1lB-hydroxy-170;,21-epoxy-1,4-pregnadiene-3,2O-dione (Compound VI) of the followingstructural formula:

' Compound. VI; (the, 60;- or 6,8:epimer) possessesgluco corticidal andanti-inflammatory properties, similar. to those of Compounds IV and V,though to a modified degree, and possesses particularly marked diureticactivity.

Alternatively, the 6-fluoro-l1,8,l7a,2l-trihydroxy-1,4-pregnadiene-3,20-dione 2l-alkyl or aryl sulfonate canfirst be convertedto the corresponding 21-iodo compound (III), which is readilyconvertible to .the 21-fluoro steroid. The 21-iodo steroid is preparedbyreacting the said 21- alkyl oraryl sulfonate with sodium, potassium orlithium iodide in an oxygenated hydrocarbon solution, e.g., an alkanonesolution, suchas acetone. A molar excess of sodium iodide (three totwenty moles of sodium iodide peryrnole of, steroid) is generallypreferredfor this reaction. The reaction mixture. containing the21-alkyl or aryl, sulfonate and sodium iodide andacetone isheatedtorefluxfor a periodof about three minutes to thirty minutes. Thethusproduced 6.-fl uoro-11,8,17-dihydroxy- 42l-iodo-1,4-pregnadiene-3,20-dione can then be isolated by evaporatingthe solvent. For the subsequent reaction, the 21-iodo steroid can beused either in purified form as a product of recrystallization from suchorganic solvents as acetone, ethanol, Skellysolve B (brand of hexanehydrocarbons), or the like, or it can'be used in the crude state in thenext step of the synthesis.

The 2l-iodo steroid, dissolved in a solvent such as acetonitrile,dimethylformamide or ethylene glycol, is treated with silver fluoride,antimony fluoride, potassium fluoride, or the like, acetonitrile, andsilver fluoride, respectively, being preferred. The metal fluorideshould be added in small quantities at intervals, and the reactionmixture should be protected from light during the reaction period, whichusually ranges from one-half to six hours. The reaction mixture is thenconcentrated and the product extracted as in the previous steps to yieldessentially pure 6 ,21-di fluoro-1l,B,17ot-dihydroxy 1,4pregnadiene-3,20- dione.

The oxidation of 6,21-difluoro-llp,l7a-dihydroxy-l,4-pregnadiene-3,20-dione is generally carried out in a conventionalmanner, such as, for example, by oxidizing the said 6,2l-diflu0rosteroid in acetic acid solution with chromic acid using molar quantitiesor a slight excess thereof, such as from ten to thirty percent excess,or by oxidizing with a halo amide or'imide of an acid, such asN-bromoacetamide, N-chlorosuccinimide, or N-brornosuccinimide dissolvedin pyridine, dioxane, or other suitable solvents. After termination ofthe oxidation reaction, the oxidant is generally destroyed by additionof an arresting agent such as methyl alcohol or ethyl alcohol for thechromic acid oxidant or a b-isulfite for chromic acid, N-bromoacetamide, N-bromosuccinimide and other N-halo acyl amides andimides. Thereafter, the resulting 6,21-difluoro-l7a-hydroxy-1,4-pregnadiene-3,1 1,20-trione is recovered byconventional means, such as by extraction with water-immisciblesolvents, e.g., methylene chloride, ethylene chloride, chloroform,carbon tetrachloride, ether, benzene toluene or the like, or bychromatography.

As hereinbefore indicated, the compounds of the present invention areadditionally useful as intermediates in the production of the valuable9a-fluoro derivatives. Thus 6,21-difluoro 11fi,17oz dihydroxy-1,4pregnadiene-3,20- dione can be dehydrated with N-bromoacetamide andanhydrous sulfur dioxide in pyridine by permitting the reaction tocontinue until a negative acidified potassium iodide-starch test of thereaction mixture is obtained. Dilution with cold water results in theprecipitation of 6,21-difluoro-17a hydroxy-1,4,9'( 1 1)pregnatriene-3,20- dione, which can be purified by recrystallizationfrom acetone. The crystalline product can then be reacted in methylenechloride-tertiary butyl alcohol solution with perchloric acid andN-bromoacetamide or N-iodosuccinimide to produce a reaction mixture fromwhich 6,21- difluoro-9a-bromo-l1/3,l7a dihydroxy-1,4 pregnadiene-3,20-dione or the; corresponding 6,2l-difll1OI'O-9a-i0d0 compound canhe, recovered by precipitation with ice water and recrystallization fromacetone. The latter compound can be reacted in acetone solution withanhydrous potassium acetate at reflux temperatures to produce6,21-difluoro-9(11)-oxido-l7a hydroxy-l,4-pregnadiene-3,20-dione, whichis recoverable from the reaction mixture by chromatography and can befurther purified by recrystallization from Skellysolve Bhexanes-acetone. Reactionofthe said 9( ll)-oxido compound in methylenechloride solution with aqueous hydrogen fluoride at room temperature isproductive of6,91%,21-t1ifl110I0-1lfi,17oL-Cllhydroxy-1,4-pregnadiene-3,20-dione.Substitution of aqueous hydrogen chloride at lower reaction temperaturesyields 6,21-difluoro-9a chloro 115,170: dihydroxy 1,4-pregnadiene-3,20-dione. If desired, either the 9a-iuoro or chloroproduct can beoxidizecl with N-bromoacetarnide in pyridine solution togive.6,9a,21-trifluoro-17ot-hydroxyl,4-pregnadiene-3,l1,20-trione or thecorresponding tchloro compound.

5 The steps of the foregoing process for'the preparation of the 9a-halosteroids may be inverted without departing from the basic concepts ofthe process. Thus, 6-fluoro- 1 113, 17u-dihydroxy-2l-acyloxy-1,4-pregnadiene-3,20-dione can be selected as the startingsteroid, the said 21-acyloxy compounds being prepared in the mannercustomarily employed for acylating hydrocortisone,'-e.g., by. reactionof the appropriate 21-hydroxy steroid with the anhydride or acid halideof an organic carboxylic. acid containing from one to twelve carbonatoms, inclusive, under conventional esterifying conditions. The said2l-acyloxy steroid can be dehydrated as by reaction withN-bromoacetamide and anhydrous sulfur dioxide in pyridine and the9a,11fl-bromohydrin formed by treatment with N- hromoacetamide in anacidic aqueous organic solution. The 9(11)-oxide group can then beintroduced by reaction of the bromohydrin with potassium acetate inacetone. Fluorination of the resulting compound produces 6,9u-difluoro-11,8,1704,21-trihydroxy-1,4-pregnadiene-3,20- dione, which can befluorinated at the 21-position-by the steps and methods earlierdescribed.

In the foregoing processes, it should be understood that either Get-haloepimer or the 618-halo epimer can be utilized at any stage. The6a-epimer' can be obtained at appropriate intermediate stages bytreatment of the 613- fcompound, at temperatures of zero degreescentigrade or slightly lower and in an organic solvent such aschloroform, with an anhydrous mineral acid, such as hydrochloric acid,in the presence of alcohol. Such temperatures should be maintainedthroughout the period of addition of the acid. The reaction mixture canthen be washed with successive portions of dilute alkali and water andevaporated under reduced pressure.

The foregoing reactions are exemplified in greater detail below. It willbe understood by those skilled in the art, nevertheless, that thespecific order of steps may be inverted or transposed or otherwisevaried to suit'the purposes of economics, convenience, or the like.

The following preparations and examples are'illustrative of the processand products of the present invention but are not to be construed aslimiting.

PREPARATION 1 -3-ethylene glycol ketal of methyl3,11-diketo-5u,6a-0xidow 17(20)-[cisl-pregnen-ZI-oate. i

To a solution of 5.0 grams of the S-ethylene-glycol ketal of methyl3,11-diketo-4,l7(20)-[cisl-pregnadien-21- oate, prepared in the mannerdescribed in US. Patent 2,707,184, in 100 milliliters of chloroform wasadded a chilled solution of 1.9 grams of perbenzoic acid dissolved in31.5 milliliters of chloroform. The solution was maintained at aboutfour degrees centigrade for 24 hours, and "then at room temperature for72 hours. The solution "was then washed with a five percent aqueoussolution of Esodium bicarbonate and then with water. The chloro- :formlayer was separated, dried and the solvent distilled 10 give a residueof 5.3 grams of solid. Crystallization ,of this solid from methanol gave2.24 grams of product melting at 180 to 195 degrees centigrade and aftertwo crystallizations from methanol, there was obtained pure 3-ethyleneglycol ketal of methyl 3,1l-dilc'eto-5a,6a-oxido-17(20)-[cis]-pregnen-21-oate melting at 206 to 209 degrees centigradehaving an [:1 of 37 degrees (CHC13) and having the analysis given below:

Analysis.--Calculated for C H O C, 69.20; H, 7.75. Found: C, 69.59; H,7.81.

PREPARATION 2 Methyl 3,11-diket0-5a,6;3-dihydr0xy-1 7(20) -allopregnen-21-oate and methyl 3,11-diketo-a-hydroxy-tifl-fluoro-17(20)-all0pregnet1-21-0ate The heterogeneous mixture was stirred fortwo hours, made slightly basic with 300 milliliters of five percentsodium bicarbonate solution, and extracted with methylene chloride. Theextract was washed, dried, and evaporated to dryness to give 1.62 gramsof crude solid. Chromatography gave two fractions: A, 481 milligramseluted with methylene chloride plus five percent acetone 'and B, 921milligrams eluted with methylene chloride plus ten and twenty percentacetone. Crystallization of fraction A from acetone-Skellysolve Bhexanes gave 390 millgrams of methyl 3,11-diketo-5oc-hydroxy-6B-fluoro-17(20)-allopregnen-21-oate, melting point 254 to 260 degreescentigrade. The analytical sample melted at 260 to 263 degreescentigrade.

Analysis-Calculated for C H O F: F, 4.84. Found: F, 4.47.

Fraction B on crystallization from acetone-Skellysolve B hexanes gave470 milligrams of methyl 3,11-diketo- 5a,6{3 dihydroxy 17(20)allopregnen-21-oate, melting point 235 to 245 degrees centigrade. Theanalytical sample melted at 245 to 248 degrees centigrade.

Analysis-Calculated for C H O C, 67.67; H, 7.74. Found: C, 67.91; H,7.62.

PREPARATION 3 diketo 5a hydroxy-6B-fluoro-17(20)-all0- pregnen-Zl-oateS-ethylene ketal A mix-ture of 1.9 grams of methyl3,11-diketo-5ahydroxy-6,8-fluoro-17(20-allopregnen-21-oate, 59milligrams of p-toluenesulfonic acid monohydrate and 31 milliliters ofdistilled ethylene glycol was added to 800 milliliters of benzene. Themixture was stirred and refluxed for two hours, with the condensatepassing through a water trap to remove the water. After reflux themixture was cooled, washed with water and evaporated to dryness to givea crude solid which on recrystallization from acetone-Skellysolve Bhexanes gave 1.96 grams of methyl 3,11 diketo 50 a hydroxy 6,8 fluoro17(20)- allopregnen-Zl-oate 3-ethylene ketal, melting point to 173degrees centigrade. Following the above procedure, substituting otherdihydric alcohols for ethylene glycol, for example, 1,2- propyleneglycol, 2,3-butanediol, 1,3-butanediol and 2,3- pentanediol isproductive of the respective 3-alkylene ketals of methyl 3,11 diketo 5ozhydroxy 6B fluoro- 17 (20) -allopregnen-21-oate.

PREPARATION 4 5 0a,] 15,21-trihydroxy-6B-fluoro-1 7 (20) -all0pregnen-3-0ne 3-ethylene ketal Methyl 3,11

To a solution of 1.96 grams of methyl 3,11-diketo-5ahydroxy 65 fluoro17(20) allopregnen 21 oate 3-ethylene ketal in 850 milliliters ofanhydrous ether was added 3.7 grams of lithium aluminum hydride and themixture was stirred for a period of one hour. 200 milliliters of waterwas added slowly and the ether phase separated. The aqueous phase wasextracted with ethyl acetate and the extracts added to the ether phase.'The combined ether-ethyl acetate solution was washed with water, driedand evaporated to dryness under reduced pressure. The crude solidresidue was crystallized firom acetone-Skellysolve B hexanes to give1.30 grams of 5a,11fi,21 trihydroxy 6B fluoro 17(20) allopregnen- 3-one3-ethylene ketal, melting point 197 to 205 degrees centigrade. Anadditional 226 milligrams was obtained from the mother liquor, meltingpoint 175 to degrees centigrade.

PREPARATION 5 5a,]1fl-dihydroxy-6B-fluoro-21-acetoxy-1 7(20) -all0-pregnen-3-one S-ethylene ketal The acetate was prepared by allowing 0.87gram of 5a,11[3,21 trihydroxy 6 3 fluoro 17(20) allopregnen- 3-one3-ethylene ketal to stand overnight in ten milliliters of aceticanhydride and'ten milliliters of pyridine.

The solution wasthen poured into ice water to give 0.92 gram of5a,1lfi-dihydroxy-GB-fluoro-Zl-acetoxy-17(20)- allopregnen-3-one3-ethylene'ketal, melting point 140 to 150 degrees centigrade, which onrecrystallization from acetone-Skellysolve B hexanes gave 0.77 gram,melting point 149 to 153 degrees centigrade.

Similarly, other 21-organic carboxylic' esters of 511,115,-21-trihydroxy-6,6-fiuoro-17(20)-allop regnen-3-one 3-ethylene ketals areprepared wherein the 21-acyloxy group is vformyloxy, propionyloxy,butyryloxy, valeryloxy, hexanoyloxy, heptanoyloxy, octanoyloxy,benzoyloxy, phenylacetoxy, or the like, by contacting5oc,l1fi,21-tl"lhydroxy-6B-fluoro-1-7(20)-pregnen-3-one 3-ethylene ketalwith an appropriate acylating agent, e.g., the anhydride or acid halideof the selected acid in a solvent such as, for example, benzene,toluene, acetic acid, or the like. A convenient method of preparing the21-formyloxy ester consists in contacting 5a,118,21-trihydroxy-6fifluoro-17(20)-pregnen-3-one 3-ethylene ketal withformic acid in thepresence of para-toluenesulfonic acid.

PREPARATION 6 5oz,11B,17a-trihydroxy-6B-fluoro-21-acetoxyaLlpregnane-3,20-dione 3-ethyleneketal To a solution of 0.77 gram of a,11B-dihydroXy-6fifiuoro 21acetoxy-17(20)-allopregnen-3-one 3-ethylene ketal in 35 milliliters oftertiary butyl alcohol was added one milliliter of pyridine, 1.9milliliters of N-methylmorphine oxide peroxide solution, and 13.1milligrams of osmium tetroxide (9.1 milliliters of tertiary butylalcohol solution containing 1.44 milligrams OsO per milliliter). Thesolution was stirred for a period of 2.5 hours, fifteen milliliters offive percent sodium hydrosulfite added, stirred for an additional tenminutes, 0.7 gram of finely ground synthetic magnesium silicate added,stirred for a period of twenty minutes more and filtered. The filtratewas taken to dryness under reduced pressure (below fifty degreescentigrade) and the residue dissolved in methylene chloride, washed withwater, dried and evaporated to dryness. This residue was crystallizedfrom acetone-Skellysolve B hexanes to give 0.47 gram of 5u,11 3,17atrihydroxy 65 fluoro-Zl-acetoxyallopregnane-3,20-dione 3-ethylene ketal,melting point 220 to 228 degrees centigrade.

PREPARATION 7 5a,11;8,17a trihydroxy 6}? fluoro 21acetoxyallopregnane-3,20-di0ne A solution of 0.47 gram of5u,11;8,17u-trihydroxy- 613- fluoro 21 acetoxyallopregnane 3,20 dione3-ethylene ketal in 35 milliliters of acetone and four milliliters of lN sulfuric acid solution was gently boiled on the steam bath for tenminutes, cooled and neutralized with dilute sodium bicarbonate solution.Addition of water andcooling gave 0.33 gram of 50:,1 1,8,17a-trihydroxy6B fluoro 21. acetoxyallopregnane 3,20- dione, melting point 230 to 240degrees centigrade.

PREPARATION 8 613 fluoro 1119,1711 dihydroxy 21 acetoxy 4 pregnene 3,20dione (613 fluorohydrocortisone acetate) A solution of 100 milligrams of5 a,11fi,17a-trihydroxy- 6B fluoro 21 acetoxyallopregnane 3,20- dione in4.9 milliliters of acetic acid and 0.1 milliliter of water was refluxedfor a period of one hour, cooled, diluted with fifty milliliters ofWater and evaporated to dryness under reduced pressure. The residue waschromatographed over Florisil (synthetic magnesium silicate) to give onefraction (77 milligrams) eluted with methylene chloride plus ten percentacetone. Crystallization from acetone- Skellysolve B hexanes gave 38milligrams of 6 3-fluoro- 116,170: dihydroxy 21 acetoxy 4 pregnene 3,20-dione (6B-fluorohydrocortisone acetate), melting point 21:0" to 21.8degreescentigrade. Infrared data. and ultraviolet data are; inagreementwith the structure.

PREPARATION 9 60a --fluoro 115,17d dihydfoxy 21 acetoxy 4 pregnene.3,20-dione (fiwfluorohydrocortisone acetate) A solution of 0.132 gram of6B-fiuoro-l 1/3,17a-dihydroxy 21 acetoxy 4 pregnene 3,20 dione in twelvemilliliters of chloroform and 0.1 milliliter of absolute alcohol wascooled to minus ten degrees centigrade in an ice-salt bath. A stream'ofanhydrous hydrochloric acid was bubbled through the solution for two andonehalf hours, at a temperature of between minus five and minus fifteendegrees centigrade. The solution was diluted with 25 milliliters ofchloroform, washed with dilute aqueous sodium bicarbonate solution,dried over anhydrous sodium sulfate, and evaporated to dryness underreducedvpressure at sixty degrees centigrade. Crystallization of theresidue from acetone-Skellysolve B solutiongave 42 milligrams of theisomerized product, 60:- fluoro 115,170 dihydroxy 21 acetoxy 4pregnene-3,20-dione,. which melted at 203 to 210 degrees centigrade.

PREPARATION 10- 6a fluoro I I e,17oz,21 trihydroxy 4 pregnene 3,20-

dione (6bz-fluorohydracortisone) and the 6 3-epimer.

thereof was neutralized. with acetic acid and distilled to remove 65-fluoro 170:,21 dihydroxy 4 pregnene 3,11,20- trione(.6B-flu0roc0rtisone) Substitution of the corresponding 6a-epimer forthe starting material above is productive of 6ot-fluOl'0-17oc,

21 dihydroxy 4 pregnene 3,11,20 trione. Alternatively, the 6ix-epimercan be obtained from the corresponding 65 product by the procedure ofPreparation 9.

PREPARATION 12 6a flizora- 11fi;1'7m,21 trihydroxy 1,4 pregnadierie-3,20-dione (A -6a-fluor0hydroc0rtisone or 6a-fluoro-1-dehydrohydrocortisone) (1) Five -milliliter portions of a medium, in250-milliliter Erlenmeyer flasks, containing one percent glucose, twopercent corn steep liquor (sixty percent solids) and tap water, wereadjusted to a pH of 4.9. This medium was sterilized-for. 45 minutes atfifteen pounds per square inch pressure and inoculated with .a one totwo day growth of Septomyxa afiinis, A.T.C.C. 6737. The Erlenmeyer flaskwas shaken at room temperature (about 26 to 28-degrees centigrade) for aperiod of three days. At the end of this period this '500-millilitervolume was used as an inoculum for ten liters of the same glucose-cornsteep liquor medium which in addition contained ten mil liliters of anantifoam compound (a mixture of lard oil and octadecanol). The fermenterwas placed in the water-bath, adjusted to 28 degrees centigrade and thecontents stirred (300 rpm.) and aerated (0.3 'liter" air to five litersof beer). After 24 hours of incubation, when a good growth had beendeveloped, five grams of 6u-fluorohydrocortisone acetate plus one-halfgram of 3-ketobisnor-4-cholen-22-al dissolved in 25 milliliters ofdimethylformamide was added and the incubation carried out at the sametemperature (28 degrees centigrade) and aerated for a period of 72 hours(final pH'8.3). The mycelium was filtered off and washed with water. Thewash water was combined with the filtrate and the whole was extractedwith three two-liter portions of a mixture of methylene-ethyl acetate(3:1). Removal of the solvent by evaporation gave 5.25 grams of crudesolid which was triturated twice with four milliliters of methylenechloride to give 2.4 grams of l-dehydro-6a-fiuorohydrocortisone ofmelting point 198m 203 degrees centigrade. The analytical sample,recrystallized from acetone, melted at 202 to 204 degrees centigrade.Analysis gave [al plus 73 degrees (dioxane) and the following:

Analysis.Calculated I for C21H3705F: C, 66.65; H, 7.10; F, 5.02. Found:C, 66.68; H, 7.19; F, 5.49.

Substitution of the 6p-epimer for the starting material above isproductive of 1-dehydro-GB-fiuorohydrocortisone. The 6p-epimer can beconverted to the 6a-epimer following the procedure of Preparation 9.

EXAMPLE 1 6a-fluoro-11BJ7a,21-trihydroxy 1,4 pregnadiene 3,20-

dione 21 -methanesulfonqte (II) Three hundred milligrams of6a-fiuoro-1lB,17a,21- trihydroxy-l,4-pregnadiene-3,20-dione wasdissolved in pyridine and cooled toatemperature of between zero and fivedegrees centigrade. 0.1 milliliter of methanesulfonyl chloride was addedand the solution maintained between zero and five degrees centigrade fortwo hours. This was poured into a solution of three milliliters ofconcentrated hydrochloric acid diluted with fifty milliliters of water.310 milligrams of crystalline6a-fiuoro-11B,17u,21-trihydroxy-l,4-pregnadiene-3,20 dione 21methanesulfonate was precipitated from the diluted hydrochloric acid.The product melted with decomposition at200 to 202 degrees centigrade.Infrared adsorption in a mineral oil mull were as follows: 3570, 3370centimeters" (OH); 1727 centirneters (20-ketone); 1665 centimeters-(conjugated ketone); 1623, 1601 centimeters" (A 1360, 1342, 1172centimeters-M040 EXAMPLE 2 60:,21-diflu0r0-116,17a-dihydr0xy-L4pregnadiene 3,20- diane (IV) A mixture of 100 milligrams of6oz-fluOrO-1lfi,17a,2ltrihydroxy-1,4-pregnadiene-3,20-dione21-methanesulfonate and fifty milligrams of potassium fluoride in onemilliliter of dimethylsulfoxide was refluxed on a steam bath foreighteen hours. The mixture was diluted with fifty milliliters ofmethylene dichloride and washed two times with ten milliliters of water.The methylene chloride solution was passed over a column of twenty gramsof Florisil (a synthetic magnesium silicate). Elution with a mixturecomposed of 91 parts of Skellysolve B (hexane hydrocarbons) and 9 partsof acetone gave a fraction of fourteen milligrams. The infraredabsorption of this compound indicated it was 6a-fiuoro-l1B-hydroxy-17a,21- oxido-1,4-pregnadiene-3,20-dione (VI). Theabsorptions in mineral oil mull were as follows: 3380 centimeters (OH);1807 centimeters- (four membered ring).

The fraction containing the principal product was eluted with a mixturecomposed of Skellysolve B and twelve to fifteen percent of acetone. Theproduct weighed 28 milligrams and after recrystallization from a mixtureof ethyl acetate and Skellysolve B yielded sixteen milligrams. Themelting point of the purified 60:,21-difll10l0-1 1B,17u-dihydroxy-1,4-pregnadiene-3,20-dione was 226 to 231 10 mull'follow:3360 centirmeters- (OH); 1725 centimeters- (ketone); 1655 centimeters(conjugated ketone); 1597 centimeters- (A EXAMPLE 3 l 7a-hydroxy-6a,21-difluoro-1,4-pregnadiene-3J1 ,20-tri0ne EXAMPLE 4 17oc-hydroxy-6a,21-diflu0r0-1,4-pregnadiene-3,11,ZO-trione In the samemanner as shown in Example 1, treating 1-dehydro-6a-fluorocortisone withmethanesulfonyl chloride in pyridine solution yielded6a-fiuoro-17m,21-dihydroxy-l,4-pregnadiene-3,11,20 trioneZI-methanesulfonate. The 6a-fiuoro-l7a,2l-dihydroxy-l,4 pregnadiene-3,11,20-trione ZI-methanesulfonate thus obtained was refluxed withpotassium fluoride in dimethylsulfoxide in the manner of Example 2 andyielded l7u-hydroxy-6a,2l-difluoro-l,4-pregnad iene-3,l1,20-trione.

Instead of the 1-dehydro-6d-fiuorohydrocortisone or -cortisone, the 68-epimers can be used in the above examples and, if the conditions arekept near neutral, the 6,8-epimers, such as6,8,2l-difiuoro-l1p,17m-dihydroxy-l, 4-pregnadiene-3,20-dione and618,21-difluoro-l7a-hydroxyl,4-pregnadiene-3,l1,20-trione, can beisolated from the reaction mixture. The thus obtained fl-epimers yieldthe 6ut-epimers by treatment with acid or base in an organic solvent,e.g., ethanol at room temperature.

EXAMPLE 5 A mixture of one gram of 11fi,17a-dihydroxy-6u,21-difluoro-l,4-pregnadiene-3,20dione, 650 milligrams of N- bromoacetamideand six milliliters of pyridine were stirred in the dark for a period ofthirty minutes. The mixture was cooled in an ice-water bath and a streamof sulfur dioxide was directed onto the surface of the stirred mixtureuntil a negative potassium iodide-starch test was obtained. Fiftymilliliters of water was then added to the mixture, and the mixture wasmaintained at about five degrees centigrade for thirty minutes. Theprecipitated white solid was filtered, washed with water and dried undervacuum. After crystallization from acetone there was obtained about 0.7gram of 17a-hydroxy-6a,21- difluoro-1,4,9 l1 -pregnatriene-3,20-dione.

0.5 gram of 17a-hydroxy-6u,21-difiuoro-1,4,9(11)-pregnatriene-3,20-dione was dissolved in twenty milliliters of methylenechloride and thereto was added a solution of one milliliter of 71percent perchloric acid in ten milliliters of water and 200 milligramsof N-bromoacetamide in fifty milliliters of tertiary butyl alcohol. Thesolution was maintained at room temperature for fifteen minutes and thenmixed with a solution of 0.3 gram of sodium sulfite in twelvemilliliters of water. The mixture was distilled at reduced pressureuntil the residual solution became cloudy. The product was thenprecipitated by the addition of 100 milliliters of a mixture ofice-water. The white crystalline precipitate was filtered, washed withwater and then dried and recrystallized from degrees centigrade.Infrared absorptions in mineral oil 75 a mixture of acetone andSkellysolve B hexane hydrovtions of acetone.

over a column of 25 grams of Florisil synthetic magnesium silicate. Thecolumn was developed with Skelly- .so'lve B hexane hydrocarbonscontaining increasing por- The Skellysolve B plus ten percent acetoneeluate contained9(11)-oxido-l7a-hydroxy-6a,2ldifiuoro-I,4-pregnadiene-3,20-dione.

A solution of one .gram of 9(11)-oxido-17a-hydroxy-6a,21-difiuoro-1,4-pregnadiene-3,20-dione was dissolved added fivemilliliters of 48 percent hydrofluoric acid and 0.5 milliliter of 71percent perchloric acid. The mixture was stirred vigorously for sixhours and then poured into an excess of cold aqueous five percent sodiumbicarbonate solution. The methylene chloridelayer was separated, driedwith anhydrous sodium sulfate, and then poured "over a column of 100grams of Florisil synthetic magnesium silicate. The column was developedwith Skelly solve B 'hexanes and acetone, and the fractions containingten percent acetone were recrystallized from acetone and Skellysolve Bhexanes to give pure 6a,9oc,21-t1'iflu0I'O-11B,l7a-dihydroxy-l,4epregnadiene 3,ZO-dione.

EXAMPLE 6 6 01,912] -trifluro-1 7a-hydroxy-1Amregnadiene-SJ1,20- trioneOxidizing, inthe same manner given in Example 3,

in [fifty milliliters of methylene chloride and thereto was -6a,9a,2'1trifluoro- 115,17 dihydroxy 1,4 pregnadiene-3,20-dione with chromicanhydride in acetic acid solution produces 6a,9cz,21 trifluoro 17-hydroxy-1,4- pregnadiene-3 ,11,20-trione.

This application is a continuation-impart of copending applicationSerial No. 699,529, filed November 29, 1957, now Patent No. 2,838,543issued June 10, 1958.

It is to beunde'rstood that the invention is not to be limited totheexact details of operation or exact compounds shown and described, asobvious modifications and equivalents will be apparent to one skilled inthe art, and the invention is therefore to be limited only by the scopeof 'the appended claims.

We claim:

1. A 6-fiuoro-17a,2l-epoxy-1,4-pregnadiene of the following structuralformula:

2. 6a fluoro 11B hydroxy 17,21 epoxy 1,4-

pregnadiene-3,20-dione.

N 0 references cited.

1. A 6-FLUORO-17A,21-EPOXY-1,4-PREGNADIENE OF THE FOLLOWING STRUCTURALFORMULA: